Gonorrhea is currently the most common reportable disease in the United States and one of the major problems throughout the world. Several factors have been suggested as responsible for the pandemic, but it is generally accepted that the lack of a blood test suitable for mass screening may be the most important factor in the failure to control the disease. The above-identified applications describe procedures for serological testing based upon the discovery of the production of a Nisseria gonorrhoeae (N.g.) antigen which is heat labile and reacts with N.g. antibodies in human sera thereby to detect the presence of a current or past gonorrhea infection. The procedures have a high specificity rate which makes it acceptable as an adjunct diagnostic test for use in voluntary screening programs. However, the social and psychological reaction to a false positive in a mandated premarital test is so unfavorable that methods of high specificity are desired.